Fig. 52.—Experiment illustrating the effect of the kind of wheat upon the size of the loaf. Courtesy of Utah Agricultural College.

Figure 52 shows the result of an experiment with flour made from different kinds of wheat, all the other factors in the bread making being identical. This effect of the difference in the composition of the flour is very striking. Again, the same variety of wheat will differ from season to season,

and the time of planting, also, affects the quality of the grain. The time of planting and reaping gives us two classes of wheat and flour, the winter and spring. Winter wheat is sown in the fall and obtains its first growth before winter, living through the winter in those latitudes where the climate is sufficiently mild, being harvested in early summer. Spring wheat is sown in the spring and harvested late and it is the wheat of the great flour-producing state, Minnesota. The difference in the composition of the two wheats is shown in this table.[13]

WaterProteinFatCarbo-
hydrate
Ash
Wheat
Spring varieties10.412.52.273.1.9
Winter varieties10.511.82.173.81.8

Note that the spring wheat contains more protein and therefore more gluten. The flour from spring wheat is creamy in color, granular to the touch, has more gluten, and is known as a strong flour. Flour from winter wheat is somewhat whiter in color and smoother to the touch, feeling more like cornstarch, and if a portion is squeezed in the hand, it retains the imprint of the fingers. It has less gluten, more starch, and is known as a soft flour. This type of flour is sometimes called “pastry flour,” the smaller percentage of gluten making it more desirable for pastry or cake than the stronger flour.

Flour manufacturers and bakers are constantly experimenting to find the best possible varieties and combinations of varieties for bread flour. Some difference of opinion exists,

but a combination of winter and spring wheat in flour is considered the best for bread by some authorities.

We must learn to like a creamy color in bread, for this means the presence of more gluten. To summarize: a good bread flour contains a large percentage of gluten, is creamy in color, and granular to the touch.

Manufacture of flour.—Modern machinery has taken the place of the old-time stones in the grinding of flour, although the two main divisions of the process remain the same, these being the crushing of the grain and the sifting out of the coarse portion. Milling now includes many stages in the process not possible with the cruder machinery of former times, and the present effects a greater number of separations and permits the miller to make a greater variety of products.